High-velocity breathing valve

ABSTRACT

A high-flow, low-resistance minimal dead space breathing valve having intake and exhaust flow paths separated but coaxial and coupled with in-line K-valves which reduce turbulence and flow resistance to a minimum. The breathing valve is particularly suitable for making very accurate maximal breathing capacity and oxygen cost determinations under conditions of severe exercise.

United States Patent Koegel 1 Feb. 22, 1972 [54] HIGH-VELOCITY BREATHINGVALVE 3,242,921 3/1966 Seeler ..128/145.5

. 3 348 539 10/1967 McDonald.... ....l28/142.2 [72] Inventor: EwaldKoegel, 946 E. Sunshine Drive, San

Antonio, Tex 78228 3,473,561 10/1969 Svenson ..l37/525 [22] Filed: Oct.21, 1970 Primary Examiner-Samuel B. Rothberg Assistant Examiner-WilliamH. Wright [21] Appl' 82656 Attorney-HarryA. Herbert, Jr. and ArsenTashjian [52] U.S.Cl ..137/512,137/512.1, 137/525 [57] ABSTRACT [51]1nt.Cl..- ..Fl6k 15/14 [58 Field ofSearch....137/525,512.1,512.1s,s12.4, A 9 dead Space breahmg 137/63 128/145 5147 142 137/512 valve having intake and exhaust flow paths separated butcoaxial and coupled with in-line K-valves which reduce turbulence andflow resistance to a minimum. The breathing valve [56] References Citedis particularly suitable for making very accurate maximal UNITED STATESPATENTS breathing capacity and oxygen cost determinations underconditions of severe exercise. 2,954,048 9/1960 Rychlik ....l37/5123,006,363 10/1961 Jackson ..137/525 5 Claims, 2 Drawing FiguresPATENTEUFEB22 I972 3.643.686

' SHEET 1 0F 2 B 1 r INVENTOR.

BY w J 'J' HIGH-VELOCITY BREATHING VALVE BACKGROUND OF THE INVENTIONThis invention relates to a high-velocity breathing valve and, moreparticularly, the invention is concerned with providing a high-flow,low-resistance minimal dead space breathing valve for making accuratedeterminations of breathing capacity and oxygen cost of severe exercise.

The dead space and flow resistance characteristics at high flow rates ofcurrently available breathing valves are such that most previousdeterminations of breathing data in physiological studies are not veryreliable. Relatively high turbulence and back pressure in the presentlyknown valves produces a marked effect on patients being tested,especially under conditions of complete exhaustion. This detrimentaleffect is caused by airflow resistance which builds up at the high flowrates. I

Another drawback of breathing valves presently in use is the dead spacewhich is required in all known designs. In making determinations ofmaximal breathing capacity, exhaled gas collection and oxygen cost undersevere exercise, it is most desirable to use a valve with an absoluteminimum of dead space and one which has very low flow resistance. Theminimal dead space permits substantially all of the gaseous matter to becollected and the low flow resistance allows full flow of air undersevere exercision.

SUMMARY OF THE INVENTION The present invention is concerned withproviding a highflow, low-resistance minimal dead space breathing valvefor situations where high flow rates are met and flow resistance must bekept to a minimum. Intake and exhaust flow paths are separated butcoaxial so that no additional dead space is added by the breathingvalve. Further, this separation of flow paths when coupled with thenovel in-line K-valves leads to appreciable reduction in turbulence andflow resistance over conventional designs. The hereinafter describedvalve is par ticularly suitable for very accurate determinations ofmaximal breathing capacity, exhaled gas collection and for studies ofthe oxygen cost of severe exercise.

Accordingly, it is an object of the invention to provide a high-velocitybreathing valve which utilizes in-line K-valves to produce very low backpressure and turbulence at all flow rates.

Another object of the invention is to provide a breathing valve whereinthe exhaust and intake flow paths are separated but remain closely inline thereby further reducing flow resistance over conventional designs.

Still another object of the invention is to provide a breathing valveuseful in a system for making an extremely accurate determination ofoxygen cost under conditions of severe exercise. No additional deadspace is added by the breathing valve.

A further object of the invention is to provide a breathing valve whichis substantially smaller and more compact than presently availablevalves while still maintaining a much lower than normal flow resistance.

A still further object of the invention is to provide a high velocitybreathing valve which is simple in construction and easily disassembledand cleaned.

These and other objects, features, and advantages will become moreapparent after considering the following detailed description taken inconjunction with the illustrative embodiment in the accompanyingdrawings wherein like members are used throughout to identify likeelements.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view in perspective ofa high-velocity breathing valve according to the invention; and FIG. 2is a view in vertical cross section of the valve of FIG. 1 in assembledcondition with arrows showing the flow direction of the intake air andthe expiration gases.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawings, thebreathing valve includes a main housing 13 with two inlet ducts l5 and17. The inlet duct 15fis provided with an inlet in-line K-valve 19 heldin position by the threaded sleeve 21. Likewise, the inlet duct 17 isprovided with an inlet in-line K-valve 23 held in position by thethreaded sleeve 25. The sleeves 21 and 25 are threadably attached to themain housing 13. The in-line K-valves 19 and 23 are conical inconfiguration and include flexible membranes 27 and 29 molded on aconical form and cemented to Y-section supports 31 and 33 which are madeto the same conical shape at one end. The conical valves 19 and 23 areunique in that they do not disturb the linearity of the airstream andhave a low opening pressure. I

The main housing 13 is designed to accommodate a standard mouthpiece(not shown) and includes a tube 35 attached to its lower end which ispreferably a tubular section of the main housing 13. The inlet ducts 15and 17 form 60 included angles with the cylindrical axis of the mainhousing 13. The exhaust duct is coaxial with the tube 35 for attachingthe mouthpiece. Within the housing 13 and coaxial therewith, there ispositioned a conical air expander 39 which allows expansion of theexhaled air as it passes toward the exhaust valve 41. This reduces thevelocity and turbulence of the exhaled air before it reaches the valve41 thereby preventing valve flutter. The exhaust valve 41 includes aflexible membrane 43 cemented to a Y-section support 45. A valve seatingelement 47 is threadably attached to the upper end of the air expander39. An outlet tube 49 is threadably attached to the housing 13 andadapted to receive the valve seating element 47 to form' the exhaustduct assembly. Various devices such as gasometer, gas bag or othercollection devices can be attached to the outlet tube 49.

The breathing valve may be constructed of any lightweight material whichis reasonably resistant to breakage and cleaning solutions. Syntheticresin materials such as Plexiglas and lmplex are especially suitable foruse as the fabrication material in the manufacture of the breathingvalve and lmplex has the added advantage of being more durable.

MODE OF OPERATION In operation, one of the primary uses of the breathingvalve is for air collection to obtain accurate expired air samples frompatients exercising at heavy workload levels. A standard mouthpiece (notshown) is attached to the breathing valve at the tube 35 and directs theair from the valve to the patients mouth.

The air enters the inlets 15 and 17 after passing through the threadedsleeves 21 and 25 and the conical K-valves l9 and 23. The K-valves 19and 23 open to allow the air to enter the main housing 13 when thepatient inhales. The air then passes through the tube 35, into themouthpiece (not shown) and then into the patients month.

When the patient exhales, the valves 19 and 23 are caused to close bythe exhalation pressure and all of the expired air passes into theconical air expander 39. The valve 41 then opens and the expired airpasses out through the outlet tube 49 to-a gasometer or gas bag foranalysis. The diameters of the inlet tube 35 and the lower end of theconical air expander 39 are so proportioned that their free areas areequal.

The breathing valve has been tested by exercision of patients on amotor-driven treadmill to exhaustion. They breathe through the valveduring the entire exercise procedure. The individuals tested were unableto detect any airway restriction during expiration or inspiration, evenat complete exhaustion. Airflow resistance measurements across thebreathing valve under clinical conditions indicate that no significantrestriction to breathing is present. In addition, no evidence of leakingor sticking of the in-llne K-valves 19, 23 and 41 was evident. The smalldead space and low resistance characteristics at all flow rates of thehereinbefore described breathing valve make it possible to determinevery accurately the maximal breathing capacity and oxygen cost underconditions of severe exercise.

Although the invention has been illustrated in the accompanying drawingsand described in the foregoing specification in terms of a preferredembodiment thereof, the invention is not limited to this embodiment orto the preferred configuration mentioned. it will be apparent to thoseskilled in the art that my invention could have extensive use in otheroperations where it is desirable to control the flow of gases such ashigh altitude oxygen mask and gas masks.

Also, it should be understood that various changes, alterations,modifications, and substitutions particularly with respect to theconstruction details can be made in the arrangement of the severalelements without departing from the true spirit and scope of theappended claims.

Having thus described our invention, what I claim and desire to secureby Letters Patent of the United States is:

1. A high-velocity breathing valve for controlling the flow of intakeair and exhaust gas to and from an individual, said breathing valvecomprising a main housing having at least one inlet duct operativelyconnected to the sidewall thereof, an inline K-valve positioned in saidinlet duct for restricting the flow of air to the inward direction, atubular section at the lower end of said main housing for attachment toa standard mouthpiece, said inlet duct being operatively connected tosaid tubular section, an exhaust section within said main housing havingan exhaust duct opening in the upper end thereof, an outlet tubeattached to said exhaust duct for connection with a gas collectiondevice, means in said exhaust section for separating the exhaust flowpath from the intake flow path while maintaining the flow paths incoaxial relationship, and an inline K-valve positioned in said exhaustductfor restricting the flow of expiration gas to the outward direction.

2. The high velocity breathing valve defined in claim 1 wherein saidmain housing is cylindrical in configuration and includes two inletducts operatively connected to the sidewall thereof forming 60 includedangles with the central axis of said main housing, each of said inletducts having an in-line K- valve positioned therein.

3. The high-velocity breathing valve defined in claim 2 wherein saidin-line K-valves are conical in configuration and include aflexiblemembrane formed by molding on a conical form, and a Y-sectionsupport shaped to the same conical form at one end, said membrane beingcemented to said Y- section support to form said K-valve.

4. The high-velocity breathing valve defined in claim 2 wherein saidmeans for separating the intake flow path from the exhaust flow pathincludes a conical air expander positioned within said exhaust section,said conical air expander serving to allow expansion of the exhaled airas it passes toward said outlet tube, thereby reducing the velocity andturbulence of the air before it reaches the in-line K-valve positionedin said exhaust duct.

5. The high-velocity breathing valve defined in claim 4 wherein thediameters of the tubular section at the lower end of said main housingand the lower end of the conical air expander are so proportioned thattheir free areas are equal, thereby preventing airway restriction duringexpiration and inspiration under severe exercise conditions.

1. A high-velocity breathing valve for controlling the flow of intakeair and exhaust gas to and from an individual, said breathing valvecomprising a main housing having at least one inlet duct operativelyconnected to the sidewall thereof, an inline K-valve positioned in saidinlet duct for restricting the flow of air to the inward direction, atubular section at the lower end of said main housing for attachment toa standard mouthpiece, said inlet duct being operatively connected tosaid tubular section, an exhaust section within said main housing havingan exhaust duct opening in the upper end thereof, an outlet tubeattached to said exhaust duct for connection with a gas collectiondevice, means in said exhaust section for separating the exhaust flowpath from the intake flow path while maintaining the flow paths incoaxial relationship, and an inline K-valve positioned in said exhaustduct for restricting the flow of expiration gas to the outwarddirection.
 2. The high velocity breathing valve defined in claim 1wherein said main housing is cylindrical in configuration and includestwo inlet ducts operatively connected to the sidewall thereof forming60* included angles with the central axis of said main housing, each ofsaid inlet ducts having an in-line K-valve positioned therein.
 3. Thehigh-velocity breathing valve defined in claim 2 wherein said in-lineK-valves are conical in configuration and include a flexible membraneformed by molding on a conical form, and a Y-section support shaped tothe same conical form at one end, said membrane being cemented to saidY-section support to form said K-valve.
 4. The high-velocity breathingvalve defined in claim 2 wherein said means for separating the intakeflow path from the exhaust flow path includes a conical air expanderpositioned within said exhaust section, said conical air expanderserving to allow expansion of the exhaled air as it passes toward saidoutlet tube, thereby reducing the velocity and turbulence of the airbefore it reaches the in-line K-valve positioned in said exhaust duct.5. The high-velocity breathing valve defined in claim 4 wherein thediameters of the tubular section at the lower end of said main housingand the lower end of the conical air expander are so proportioned thattheir free areas are equal, thereby preventing airway restriction duringexpiration and inspiration under severe exercise conditions.